1. Field of the Invention
The present invention relates, among molds for injection molding a material such as molten synthetic resins, to a slide core mold for injection molding synthetic resins, in which an undercut core for molding a depression or the like separately from a main molding in a peripheral edge lower portion of a molded article is slidably moved in and out of a side edge of a main core.
2. Description of the Prior Art
Generally, undercut molding for molding a depression and a cut separately from a main molding in a peripheral edge lower portion of a molded article should be performed by protruding an undercut core for molding an undercut portion into a recess of a core mold separately from a core mold which is a main body. Therefore, in the past, a slide core mold provided with a slide mechanism portion has been used in which when a mold is opened to remove a molded article, an undercut-portion molding core protruded into a recess of the molded article can be moved backward in association therewith so as to remove the molded article. In the past, the slide mechanism of the type as described is designed so that an undercut core and a slider block provided with an inclined hole are slidably provided on the side of a core mold, an inclined pin is provided at a corresponding position of a cavity mold corresponding to a position of said inclined hole, the slider block being moved forward and backward while being guided according to a degree of fitting of the inclined pin into the inclined hole.
However, in the conventional slide mechanism using the inclined pin and the inclined hole, the pin is caught so that it may not be fitted into the hole unless the angle of inclination thereof is precisely met the pin and the hole, and therefore, extremely high precision is required. In addition, the steps of manufacturing a mold increases thus making it difficult to manufacture a mold. Moreover, there gives rise to a problem in that where the width of the slider is large, a partial guide merely using two points on opposite sides of the slider is unstable, and therefore, it is necessary to increase the number of guiding inclined pins and to enlarge the diameter of the pin.